1. Field of the Invention
The present invention is related to an integrated photovoltaic modular panel for a curtain wall More specifically, it is related to a photovoltaic panel with amorphous silicon thin film solar cells.
2. Description of the Related Art
Currently, solar cells are connected together by conductive wires to form a panel with hollow glass or laminated glass. Positive electrodes or negative electrodes on every photovoltaic panel solar cell are connected in either series or parallel. The internal wires are soldered together with an external lead. The more solar cells are connected in parallel, the lower is the mounting efficiency. Regardless of types of power supply systems, e.g., a stand-alone system or a networked system, the core of a PV system remains a photovoltaic panel made of solar cells. A thin film solar cell does not use a silicon wafer. Instead, it uses a nanometer semiconductor active layer deposited on an inexpensive substrate, such as glass. Thus, material cost is greatly reduced. In addition, there are benefits in manufacturing under a lower temperature than otherwise and a larger size thin film solar cell can be produced.
At present, the photovoltaic panels made from crystal or amorphous silicon solar cells can be used as curtain-wall building materials. A peak power of an amorphous silicon solar cell can reach above 60 Wp. With larger area and better rigidity, the amorphous silicon solar cell is suitable for making large and extra-large size photovoltaic panels being used as photovoltaic curtain wall glasses. Buildings built by this material meet the second security standard requirements due to good rigidity and high insulation. In accordance with industrial standard requirements for battery material, the photovoltaic panel can last more than 10 years even used in a tough environment with temperatures ranging from positive 90 degree to negative 50 degree Celsius.
A metal frame for supporting solar cells is disclosed in the Chinese invention (application number 200410028002.8), where solar cells are amorphous silicon solar cells which could be large in size, high in rigidity and few in electrode connections. In addition, the solar cells are easy to form into a desirable patterns for light transmission and adaptable to conform with architecture aesthetic demands. An issue associated with increasing photovoltaic panels being used as curtain wall glass is that the assembly process can become very complicated and time consuming for the large number of electrodes. The inner structure of the curtain wall glass may need to be changed resulting in occupying more space for transportation. In addition, this makes maintenance work more difficult, because for example, the whole frame needs to be dismantled to replace a broken solar cell.